Unit 7: Chemical Quantities

Moles <-->Volume

After today, you will be able to…

•Calculate the volume of a gas at STP given the number of moles and vice versa•Perform two step volume conversions (Ex: atoms to liters)

Mole Volume Conversions

For one mole of any gas at STP, the volume occupied will be 22.4 liters.

STP = standard temperature and pressure= 0 degrees Celsius and 1 atmosphere

1 mole gas = 22.4 L gas

Example: How many moles of Helium gas will occupy a volume of 149.3L at STP?

K: 149.3L HeU: ? mol He

149.3 L He1

x22.4 L He

1 mol He .= 6.665 mol He

2-Step Conversions with Volume, Mass, and Particles

How to convert moles into particles and vice versa by using the conversion factor…

1 mole = 6.02x1023 atoms, molec. or F.U.

How to convert moles into grams and vice versa by using the conversion factor…

1 mole = atomic mass in grams

How to convert moles into liters and vice versa by using the conversion factor…

1 mole = 22.4 L

We have already learned…

All Roads Lead to the Mole

MOLE

1 mole = 6.02 x 1023 particles

1 mole = 22.4 Liters

1 mole = (Molar Mass) grams

# of particles

(atoms, molecules or formula units)

# of grams

# of liters

Example: What volume would 4.32x1023 atoms of Krypton gas occupy at STP?

K: 4.32x1023 atoms KrU: ? L Kr

4.32x1023 atoms Kr

1x6.02x1023 atoms Kr 1 mol Kr . =

16.1 L Kr

x 22.4 L Kr .

1 mol Kr .